Motor control device, motor drive device, motor system, and electrical apparatus

Abstract

The present disclosure provides a motor control device that realizes a drive signal for each phase in a three-phase modulation control system with an analog circuit. The motor control device includes a generator, a modulation unit and inverting unit. The generator is configured to receive an input voltage and generate an analog voltage having a crest value corresponding to the input voltage and having a reference potential or higher. The modulation unit is configured to generate a PWM voltage based on the analog voltage output from the generation unit. The inverting unit is configured to invert a duty in a predetermined period of the PWM voltage.

The invention claimed is: 
     
       1. A motor control device, comprising:
 a generation unit, configured to receive an input voltage and generate an analog voltage having a peak value corresponding to the input voltage and equal to or greater than a reference potential; 
 a modulation unit, configured to generate a PWM voltage based on the analog voltage output from the generation unit; and 
 a reverse unit, configured to invert a duty of the PWM voltage during a predetermined period. 
 
     
     
       2. The motor control device of  claim 1 , wherein
 the modulation unit is configured to compare the analog voltage and a triangular wave voltage to generate the PWM voltage, and 
 the reference potential is greater than a minimum value of the triangular wave voltage. 
 
     
     
       3. The motor control device of  claim 2 , wherein the reference potential is equal to a midpoint potential of the triangular wave voltage. 
     
     
       4. The motor control device of  claim 1 , wherein the reverse unit is configured to set the predetermined period based on a rotor position of a motor. 
     
     
       5. The motor control device of  claim 1 , wherein the generation unit includes a two-phase modulation control mode and a three-phase modulation control mode. 
     
     
       6. The motor control device of  claim 5 , wherein when the generation unit operates in the two-phase modulation control mode, the reverse unit is in a state where a reverse operation is stopped. 
     
     
       7. The motor control device of  claim 5 , wherein the generation unit is configured to switch between the two-phase modulation control mode and the three-phase modulation control mode according to a rotational speed of a motor or the input voltage. 
     
     
       8. A motor drive device, comprising:
 an inverter unit, configured to convert DC voltage to AC voltage; and 
 the motor control device of  claim 1 , configured to perform switching control on the inverter unit. 
 
     
     
       9. A motor system, comprising:
 a motor; and 
 the motor drive device of  claim 8 , configured to drive the motor. 
 
     
     
       10. An electrical device comprising the motor system of  claim 9 .